If while you’re making your argument, the only time the other side is silent is because they’re thinking about their own argument, they’ve got a voice in their head that’s talking to them. They’re not listening to you. When they’re making their argument to you, you’re thinking about your argument, that’s the voice in your head that’s talking to you. So it’s very much like dealing with a schizophrenic.
If your first objective in the negotiation, instead of making your argument, is to hear the other side out, that’s the only way you can quiet the voice in the other guy’s mind. But most people don’t do that. They don’t walk into a negotiation wanting to hear what the other side has to say. They walk into a negotiation wanting to make an argument. They don’t pay attention to emotions and they don’t listen.